I wouldn't buy a laptop unless mobility was an absolute must, and even then depending on the task, I'd only get something cheap and use it intermittently. I.e. term lab testing in a car.
For anything else a desktop pc is a must. I'll goto newegg and build one myself.
Also, I had a hp "desktop replacement" laptop. Don't get an HP...
me and my friend had one...The batteries dont last long, and the charger plug to the laptop loosens overtime and if you move the laptop without holding it in place the power dies and it shuts off. eventually I had to keep tension on the cord to keep it from shutting off, even then it dies randomly. My friend's laptop's screen started screwing up, he has to bang on it to get the colors back to normal, I guess it's a loose ribbon cable inside the screen, but they're a pain to take apart and fix it. And it may not be the problem...they're just not very durable. Dropped it once out of my locker inside a bag (3.5' high), took out the screen, had to get it replaced, tech support wiped my hard drive.